# Statistics

Juan makes a measurement in a chemistry laboratory and records the result in his lab report. The standard deviation of students' lab measurements is 10 milligrams. Juan repeats the measurement 3 times and records the mean (x-bar) of his 3 measurements.

a) What is the standard deviation of Juan's mean result? (that is, if Juan kept on making 3 measurements and averaging them, what would be the standard deviation of all his means?)

==> I don't quite understand this concept...can someone please explain this to me? Thanks! :)

1. 👍 0
2. 👎 0
3. 👁 738
1. Standard deviation of a distribution of means = standard error of the mean = SEm

SEm = SD/√(n-1)

1. 👍 0
2. 👎 0
2. 7.071?

1. 👍 0
2. 👎 0
3. stnddev./squrrt of 3 =5.77 or 6

1. 👍 0
2. 👎 0

## Similar Questions

1. ### English

1. In “The Censors,” Juan chooses to apply for a ob as a government censor for all of the following reasons except. A. He fears for Mariana’s safety in her new home. B. He plans to intercept and approve his own letter. C. He

2. ### Science

3. How does the study of science benefit society? A. Non scientists in society often use the same experiments conducted by scientists in the laboratory. B. The study of science helps slow down a fast paced society. C. The study of

3. ### physics

An astronaut on the Moon attaches a small brass ball to a 1.00- m length of string and makes a simple pendulum. She times 15 complete swings in a time of 75.0 seconds. From this measurement she calculates the acceleration due to

4. ### science

Which options correctly identify a section or part of a typical laboratory report? (Select all that apply) materials procedure acknowledgements objective A,B,D?

1. ### Math

Information: Juan plans to build a bookcase t store his paperback books, DVDs, and CDs. he has lumber that he will use for the sides and back of the bookcase. Juan plans for his bookcase to have five shelves including, the top and

2. ### chemistry

In a laboratory experiment, the density of a concentrated sugar solution was determined by measuring the volume of the solution and corresponding mass. Three students each made a set of measurements using a different balance and

3. ### physics

A. What is the mass of a book that weighs 3.20 N in the laboratory? B.In the same lab, what is the weight of a dog whose mass is 14.0 kg?

4. ### English

Which of the following situations in "The Censors" represents an example of situational irony? A. Juan ends up being executed after censoring his own love letter to Mariana. B. Juan decides to report a colleague for trying to

1. ### Language Arts

Which of the following situations in "The Censors" represents an example of situational irony? A) Juan ends up being executed after censoring his own love letter to Mariana. B) Juan decides to report a colleague for trying to

2. ### chemistry

answers to latenite labs chemistry lab#9 stoichiometry by loss of CO2

3. ### physics

A. What is the mass of a book that weighs 3.20 N in the laboratory? B.In the same lab, what is the weight of a dog whose mass is 14.0 kg?

4. ### Chemistry Lab

Im preparing my report for Synthesis of Alum chemistry lab. Need help with these 2 questions: 1-What other cations besides aluminum can be used to make alum crystals? Explain 2-Why we need to add sulfuric acid slowly to the